No other large-scale health intervention can have as big an impact on child mortality as vaccination. Across the world millions of lives have been saved by innoculation, and in the past ten years the annual number of measles cases worldwide has dropped from one million to 200,000. But just as important as creating new vaccines is ensuring that children have access to them. Join us at the Oxford Martin School as Dr Matthew Snape, Consultant in Vaccinology at the Oxford Radcliffe Hospitals NHS trust and Honorary Senior Clinical Lecturer at the University of Oxford, looks at the challenges involved in making sure the success story of childhood vaccination can be a global one.